Early childhood caries (ECC) is the most prevalent chronic disease among preschool aged children in the U.S. In an effort to prevent ECC, leading organizations now encourage dental visits for all children by their first birthday, but the effects of this recommendation on dental outcomes are largely unknown. Three recent studies on the cost effectiveness of an early dental visit show conflicting results. Moreover, increasing dental visits among young children may reduce access to care for older children if the dental workforce is limited. The purpose of this study is to determine the effects of initiating regular preventive dental care at a young age on dental treatment, dental costs and dental caries history. The first two study aims rely on a longitudinal cohort design in which Medicaid-enrolled children who had a preventive dental visit before the age of 5 and those who did not have any preventive dental care by that age are compared to determine the effect of initiating regular preventive care at a young age on dental treatment utilization and costs. The primary data source for these aims is NC Medicaid enrollment and claims files from October 1999 to June 2006 that includes information for all children born on or after January 1, 1998. The third study aim is addressed through a retrospective cohort study that measures the effect of initiating regular preventive dental care at a young age on subsequent dental caries history. The primary data source for Aim 3 is the North Carolina Surveillance of Dental Caries which contains estimates on dental caries experience for almost all kindergarten students in the state for each academic school year beginning in 1997 and has been linked to the Medicaid claims files. Results of the study can inform practice guidelines and Medicaid policy on the recommended age of the first dental visit.